@charlie: I live in semi-rural New Hampshire, in a small pocket of wealth surrounded by agriculture and poverty. The people in my town had the choice of buying fuel-efficient cars (we even have public buses, too). Residents of the neighboring town, which doesn't pave the roads or shovel the snow? Not so much. All the people nearby who have never owned, have never even considered purchasing, a new car, because they can't afford to make such a large up-front investment, even if it would save them money over five or ten years? Not so much.

I take your point about the increase in elasticity, but that increase hasn't been uniform.